EXTERNAL CHARACTERS AND HABITS 95
prognathism increases the general facial appearance alters. When the lips are retracted in life the huge canine teeth give the animal a very brutal appearance.
which is intensified if it draws down the hairv crest.
which runs along the sagittal line of the head.
FIG. 19A,—The hand of the Bornean Gibbon (A) and Orang-Outan (B) showing the flexure grooves (thick lines) and papillary ridges (fine lines).
The neck is short, and the head is held more rigid than in the Chimpanzee. The thorax is short, wide and deep, and the abdomen protrudes as a large paunch.
The hand is relatively shorter and wider than in the other Apes, and the proportions of the palm approximate